The Design And Realization Of Embeded Lithium-ion Battery Formation Modeule

With the outbreak of the energy crisis, lithium batteries become the world’s hotspots again. However, as industry downstream products of lithium batteries, LithiumBattery Formation System also ushered in a new challenge. The existing FormationSystem always has many problems to be solved. Someshortcomings of existingequipment are list as bellow. It only can control small number of lithium battery whichcan’t meet the demand of the industrial production. Some systemmust bundle batteriesinto pack, and do not have the capacity of formation each battery independently.Alsosome other whose formation process is fixed,can’t change formation process asdemand.In response to these problems, this paper presents alithium battery formationcontrol module relying on embedded technology. The module uses the STM32asthemicrocontroller, its main contents are as bellow.1.The design and implementation of controlling lithium batteriesformationprocess.FormationControl Module is the part of Formation System, which manage eachlithium batteriesindependently. The module’s controlled object is minimized to theindividual cell lithium battery, and this module resolvedthe problem of the battery packas controlled object.And it set different formation process for each lithium batterywhich enhanced the system control flexibility and adapted different formationrequirementsof the individual battery.At the same time, Formation process can be setby user optional, and it allow stop, continue, pause and internal resistance detectionduring formation period.2.The design and implementation of controlling lithium battery charge anddischarge.As the demand of lithium battery charge and discharge output stability, theFormationControl Module select PID algorithm to achieve the stability of the chargeand discharge voltage and current output. As nonlinear factors of DC/DC,when set a charge or discharge value on the DC/DC module, there is deviation between output andset value. After introduction of the PID algorithm, using charge or discharge output asfeedback, the deviation can be down to0.5%FS.3. The design and implementation of lithium battery parameters high-precisiondetection.Lithium battery detection parameters include voltage, current, temperature,electric quantity, internal resistance, and so on.Some of the parameters are used tojudge whether safety or not. So the accuracy of parameter detection is very important.This system use digital filtering algorithms and channel automatic error compensationto make the detection accuracy.4. The research of energy cycle control strategy.Using48V DC bus, as the energy transfer medium, energy controller make theenergy transfer in the energy dissipation resistance, lithium battery, large capacitybattery, AC/DC.This strategy realizes the reuse of lithium battery discharge energy.The energy cycle control strategy is effective to save electric energy, greatly loweringthe cost of lithium-ion battery formation.This paper mainly describes the embedded software design of lithium batteryformation control module.From the result of running Formation System, this moduleachieved the original design goals, andresolved some problemsin existing Formationequipment. This module has successfully applied on the Formation Control System,which make the system has intelligent control, parameter precision, large scaleproduction, and energy efficiency.